It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "Your example and the example of the Jews and Christians before you is like that of a man who hired labourers and said: 'Who will work from morning until midday for one qirat?' So the Christians worked. Then he said: 'Who will do this work from midday until Asr for one qirat?' The Jews did this work. Then he said: 'Who will work from Asr until Maghrib for two qirats?' And it was you who worked. The Jews and Christians became angry and said: 'Why is it that we do more work and receive less wage?' The man said: 'Have I given you less than your due?' They said: 'No.' Then he said: 'That is my bounty; I give it to whomever I will.'"
Hadith Referenceالسنن الكبرى للبيهقي / كتاب المساقاة / 11644